* Changing all isinstance(STUFF, str)' to isinstance(STUFF, basestring)'

for future-proofing this code.

db/file_db.py

@@ -48,7 +48,7 @@ class file_table(object):
   def __init__(self, src_name, table_name='filedb', extra_fields=[]):
     self.src_name = src_name
     self.table_name = table_name
-    if isinstance(src_name, str): # os.path.isfile(src_name):
+    if isinstance(src_name, basestring): # os.path.isfile(src_name):
       self.db = sqlite3.connect(src_name)
       self.dbc = self.db.cursor()
     elif isinstance(src_name, sqlite3.Connection):

db/result_base.py

@@ -62,7 +62,7 @@ class result_base(dict):
     if isinstance(src, dict):
       self.clear()
       self.update(src)
-    elif isinstance(src, str):
+    elif isinstance(src, basestring):
       # WARNING: Awaiting future definition of parse_text_file_().
       # This must be specified in the derived class.
       self.parse_file_(src)

db/tables.py

@@ -37,7 +37,7 @@ class simple_table(object):
   def __init__(self, src_name, table_name, dtypes=None):
     self.src_name = src_name
     self.table_name = table_name
-    if isinstance(src_name, str): # os.path.isfile(src_name):
+    if isinstance(src_name, basestring): # os.path.isfile(src_name):
       self.db = sqlite3.connect(src_name)
       self.dbc = self.db.cursor()
     elif isinstance(src_name, sqlite3.Connection):